A sliding valve comprises a valve housing (10, 12) with a flow passage between an inlet (14) and an outlet (16). The valve has an orifice plate (20) with a throughflow opening and a slide (18) which has a throughflow opening with at least one region (30) of slit-like design. The valve is characterised in that a rib (28) is provided upstream or downstream of the region (30) of slit-like design, as seen in the direction of flow. <IMAGE>
